Wireless networks, in which a user equipment (UE) such as a mobile handset communicates via wireless links to a network of base stations or other wireless access points connected to a telecommunications network, have undergone rapid development through a number of generations of radio access technology. The initial deployment of systems using analogue modulation has been superseded by second generation (2G) digital systems such as GSM (Global System for Mobile communications), typically using GERA (GSM Enhanced Data rates for GSM Evolution Radio Access) radio access technology, and these systems have themselves been replaced by or augmented by third generation (3G) digital systems such as UMTS (Universal Mobile Telecommunications System), using the UTRA (Universal Terrestrial Radio Access) radio access technology. Third generation standards provide for a greater throughput of data than is provided by second generation systems; this trend is continued with the proposals by the Third Generation Partnership Project (3GPP) of the Long Term Evolution (LTE) system, using E-UTRA (Evolved UTRA) radio access technology, which offers potentially greater capacity and additional features compared with the previous standards. WiMax systems using radio access technology to IEEE 802.16 also offer improvements over previous standards.
Wireless networks typically require measurement data to be gathered, for functions such as mobility management (e.g. handover) and radio resource management (e.g. which resources to allocate to a UE). More recently measurements have been introduced to support self optimisation of networks as well as to verify if the network is deployed well e.g. proper coverage (thereby minimising the need for so-called drive tests). In particular, it is beneficial to know the strength of signals received form wireless nodes such as base stations as a function of location. This information may be used to deduce the location of coverage holes in the network, such as due to shadowing by buildings, to detect areas of weak coverage, or areas of overshoot coverage, where coverage from a cell of the wireless network extends beyond what was planned. Measurement data may also be used to detect interference such as interference between pilot signals from different cells, and to deduce coverage areas for uplink signals. Coverage mapping, of areas with strong as well as weak signals, may depend on measurement data.